4WD Problems need help please.

**Tiny1987** · 03-13-2009, 02:14 AM

ok 2004 chev silverado crew cab 1500. have noticed that when either auto 4wd or just 4wd is turned on there is a kind of howl noise in the front end when slowing to a stop. but when in 2wd it sounds fine. even switching from 4wd to 2wd while it is making the noise makes it go away. also when in auto 4wd and service 4wd light comes on it will not make the noise. could the encoder motor be causing this or could it maybe be some water intrusion on some wires? i could really use any input on this one please. i have checked for codes in the transfer case and only find a history code which i think is c0374 which they call just a generic malfunction. thanks for any input.

**silveradotrailblazer** · 03-13-2009, 02:24 AM

Ive never experianced that with my 05, but I heard that if you are on a hard surface in 4wd the front makes ,as discribe to me a rumble noise.

**Tiny1987** · 03-13-2009, 02:37 AM

this sounds about the same as a bad wheel bearing at highway speeds.

**Jimmiee** · 03-13-2009, 09:20 AM

Originally Posted by Tiny1987

this sounds about the same as a bad wheel bearing at highway speeds.

The very first thing to do is check the oil in the differential. The axle seals can leak and I have seen these diffs run dry. If the oil's OK you may have a bad U Joint. Best bet is to get it up on a hoist and run it in the air so you can find the problem.